Night vision systems generally comprise a number of components. A front lens system collects infrared light from the environment and provides the light to a night vision tube. The tube magnifies the number of received photons. In a typical tube, incoming light strikes a photocathode plate causing the emission of electrons through a microchannel plate. The electrons then form an image on a photocathode. An eye piece then conditions the image for the viewer. The tube is usually contained within a housing that is threaded at either end to mate with the front lens system and the eye piece.
In one such system, a resilient sleeve and a front compression buffer fabricated from plastic surround the tube within the housing. A retaining ring engages threads in the rear of the housing and is used to compress the sleeve against the front compression buffer and the housing. The sleeve can include an electronics path for connecting power from a battery pack to electrical contacts on the night vision tube. This electronics path can include electrical conductors extending between the battery pack, through routing cutouts formed in the sleeve to the electrical contacts. See U.S. Pat. Appl. Publ. No, US 2016/0048001 A1 by Robert Joseph McCreight, JR., which is incorporated herein by this reference. This system can also allow for retrofitting a smaller night vision tube into a housing designed for a larger tube.